Communication apparatus, access point management apparatus, selective communication connection method, and non-transitory computer readable medium

ABSTRACT

A communication apparatus according to the present disclosure functions as an access point, transmits/receives information to be shared that should be shared with another access point when a radio communication connection has been requested from a first client, and calculates, for the access point and the other access point, scores that indicate priority as a connection destination of the first client using the information to be shared. Then it is determined whether it is necessary to establish the radio communication connection with the first client based on the above scores and establishes, when it is determined that it is necessary to establish the radio communication connection, the radio communication connection with the first client.

TECHNICAL FIELD

The present disclosure relates to a communication apparatus, an accesspoint management apparatus, a selective communication connection method,and a selective communication connection program, and more particularly,to a communication apparatus, an access point management apparatus, aselective communication connection method, and a selective communicationconnection program for selectively establishing a radio communicationconnection with a client.

BACKGROUND ART

In recent years, with the spread in use of a communication apparatusthat functions as an access point in a wireless Local Area Network(LAN), a wireless LAN system including a plurality of access points hasbeen used in various places such as offices and public facilities.Various techniques for selecting an optimal access point for a client toconnect in this wireless LAN system have been proposed.

For example, in the wireless LAN system disclosed in Patent Literature1, a cost is calculated based on a radio wave intensity of a wirelessLAN client received by an access point and the number of wireless LANclients already connected to the access point, and an access point whosecost is the smallest is selected as the optimal access point.

CITATION LIST Patent Literature [Patent Literature 1] Japanese PatentNo. 6233901 SUMMARY OF INVENTION Technical Problem

However, when there are both a wireless LAN client for high-speedcommunication and a wireless LAN client for low-speed communication inthe wireless LAN system disclosed in Patent Literature 1, it is possiblethat these wireless LAN clients may connect to one access point. In thiscase, while the wireless LAN client for low-speed communication isperforming data communication with an access point, the wireless LANclient for high-speed communication needs to wait, which may cause around-trip time between the wireless LAN client for high-speedcommunication and the access point to increase.

The present disclosure has been made in view of the aforementionedproblem and aims to provide a communication apparatus, an access pointmanagement apparatus, a selective communication connection method, and aselective communication connection program capable of reducing around-trip time between the client and the access point in acommunication system including a plurality of access points.

Solution to Problem

A communication apparatus according to the present disclosure functionsas an access point, and includes: an information sharing unit configuredto transmit/receive, when a radio communication connection has beenrequested from a first client, information to be shared with anotheraccess point; score calculation unit configured to calculate, for theaccess point and the other access point, scores indicating theirpriority as a destination to which the first client is connected usingthe information to be shared; a connection necessity determination unitconfigured to determine whether or not it is necessary to establish aradio communication connection with the first client based on the scorescalculated by the score calculation unit; and a connection processingunit configured to establish a radio communication connection with thefirst client when the connection necessity determination unit hasdetermined that it is necessary to establish the radio communicationconnection. The information to be shared includes information indicatingthe presence or the absence of a second client that has alreadyestablished the radio communication connection with an access point. Thescore calculation unit calculates a score for giving a high-orderpriority to an access point in which the radio communication connectionwith the second client has not been established based on the informationindicating the presence or the absence of the second client. Theconnection necessity determination unit determines that it is necessaryto establish the radio communication connection with the first clientwhen the score of the access point is the highest among the scorescalculated by the score calculation unit.

Advantageous Effects of Invention

According to the present disclosure, it is possible to provide acommunication apparatus, an access point management apparatus, aselective communication connection method, and a selective communicationconnection program capable of reducing a round-trip time between theclient and the access point in a communication system including aplurality of access points.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view showing one example embodiment of acommunication system according to the present disclosure;

FIG. 2 is a block diagram showing a detailed configuration of acommunication apparatus according to a first example embodiment of thepresent disclosure;

FIG. 3 is a block diagram showing a schematic configuration of thecommunication apparatus according to the first example embodiment of thepresent disclosure;

FIG. 4 is a sequence diagram showing one example of processing executedin a communication system according to the first example embodiment ofthe present disclosure;

FIG. 5 is a flowchart showing processing executed by the communicationapparatus according to the first example embodiment of the presentdisclosure;

FIG. 6 is a flowchart showing processing executed by the communicationapparatus according to the first example embodiment of the presentdisclosure;

FIG. 7 is a flowchart showing processing executed by the communicationapparatus according to the first example embodiment of the presentdisclosure;

FIG. 8 is a flowchart showing one example embodiment of scorecalculation processing;

FIG. 9 is a diagram showing one example of a client information table;

FIG. 10 is a diagram showing one example of an access point score table;

FIG. 11 is a diagram showing one example of a score calculation policy;

FIG. 12 is a block diagram showing a detailed configuration of acommunication apparatus according to a second example embodiment of thepresent disclosure;

FIG. 13 is a block diagram showing a schematic configuration of acommunication apparatus according to the second example embodiment ofthe present disclosure;

FIG. 14 is a sequence diagram showing one example of processing executedin a communication system according to the second example embodiment ofthe present disclosure; and

FIG. 15 is a flowchart showing processing executed by an access pointmanagement apparatus according to the second example embodiment of thepresent disclosure.

DESCRIPTION OF EMBODIMENTS First Example Embodiment

Hereinafter, with reference to the drawings, a first example embodimentof the present disclosure will be described. FIG. 1 is a schematic viewshowing one example embodiment of a communication system 100 accordingto the present disclosure. The communication system 100 includescommunication apparatuses 10 a-10 e that function as access points (eachof them will be represented by AP in the drawings described below), anda client (it will be represented by CL in the drawings described below)20. Each of the communication apparatuses 10 a-10 e is connected to awired LAN (not shown) and data communication between the communicationapparatuses 10 a-10 e is mainly performed by the wired LAN. On the otherhand, data communication between the communication apparatuses 10 a-10 eand the client 20 is performed mainly via a wireless LAN.

The communication apparatuses 10 a-10 e are apparatuses that areconnected to a modem (not shown) connected to a telephone line or anoptical network unit (not shown) connected to an optical line andperform data communication between various types of data servers (notshown) and the client 20 via the Internet or a network such as a WideArea Network (WAN). A communication apparatus such as a wireless LANrouter is assumed as an example of the communication apparatuses 10 a-10e.

The client 20 is a communication apparatus such as a smart phone, a PC,a tablet terminal, a home electric appliance, or a sensor capable ofperforming data communication via radio waves. The client 20 broadcastsa probe request for requesting communication connection via the wirelessLAN and establishes radio communication connection with an access pointthat has transmitted a probe response in response to the probe request.The probe request includes information indicating a maximumcommunication speed of the client 20.

FIG. 2 is a block diagram showing a detailed configuration of thecommunication apparatus 10 a according to the first example embodimentof the present disclosure. Hereinafter, the configuration of thecommunication apparatus 10 a will be described. The communicationapparatuses 10 b-10 e also have configurations similar to that of thecommunication apparatus 10 a.

The communication apparatus 10 a includes a Central Processing Unit(CPU) 110, a PHY chip 120, a wireless LAN interface 130, a wired LANinterface 140, and a storage apparatus 150. The CPU 110, the PHY chip120, the wireless LAN interface 130, the wired LAN interface 140, andthe storage apparatus 150 are connected by a wire made of copper or thelike.

The CPU 110 is an arithmetic apparatus that executes various kinds ofprograms. The CPU 110 extends a selective communication connectionprogram according to the present disclosure stored in a Read Only Memory(ROM) to a Random Access Memory (RAM) and executes the above program,thereby achieving a selective communication connection method accordingto the present disclosure. The selective communication connectionprogram includes a controller 111, an information sharing unit 112, ascore calculation unit 113, a connection necessity determination unit114, and a connection processing unit 115, which are program modules.

The controller 111 plays a main role of achieving the function of thecommunication apparatus 10 a and executes various types of processing bycontrolling other program modules or function units. The controller 111acquires, when the communication apparatus 10 a has received a proberequest from the client 20, the radio wave intensity of the client 20from a radio wave intensity measurement unit 122 of the PHY chip 120 andthe maximum communication speed of the client 20 included in the proberequest. The controller 111 registers the radio wave intensity and themaximum communication speed of the client 20 in a client informationtable 152 as shown in FIG. 9.

FIG. 9 is a diagram showing one example of the client information table152. The client information table 152 registers the maximumcommunication speed and the radio wave intensity of the connectionrequest client who has requested the radio communication connection andthe maximum communication speed of the connected client who has alreadyestablished the radio communication connection with an access point.While the maximum communication speed of one connected client isregistered in the client information table shown in FIG. 9, when aplurality of clients have established the radio communication connectionwith the communication apparatus 10 a, maximum communication speeds of aplurality of connected clients are registered.

Further, when the communication apparatus 10 a has received the proberequest from the client 20, the controller 111 registers, in an accesspoint score table 153 as shown in FIG. 10, the information on theconnection request client and the information on the connected client inassociation with the identification information of the communicationapparatus 10 a.

FIG. 10 is a diagram showing one example of the access point score table153. In the access point score table 153, the information on theconnection request client and the information and the score of theconnected client are registered in association with the access pointidentification information. The information on the connection requestclient includes information indicating whether or not the access pointidentified by the access point identification information has received aprobe request from the connection request client, and the maximumcommunication speed and the radio wave intensity of the connectionrequest client. The information on the connected client includesinformation indicating whether or not the access point identified by theaccess point identification information includes a connected client andthe maximum communication speed of the connected client.

The information sharing unit 112 is a program module thattransmits/receives and shares the information to be shared, which isinformation that should be shared among the plurality of access pointsincluded in the communication system 100. The information to be sharedincludes (1) information indicating whether or not the probe requestfrom the connection request client has been received, (2) informationindicating the presence or the absence of the connected client, (3) themaximum communication speed of the connection request client and themaximum communication speed of the connected client, and (4) theintensity of the radio waves of the connection request client receivedby the access point.

When the communication apparatus 10 a has received a probe request fromthe client 20, the information sharing unit 112 refers to the accesspoint score table 153, acquires the information to be shared associatedwith the identification information of the communication apparatus 10 a,and transmits this information to be shared to another access point. Theinformation sharing unit 112 registers, upon receiving the informationto be shared from the other access point, this information to be sharedin the access point score table 153 in association with the specificidentification information of the other access point.

Further, the information sharing unit 112 broadcasts the informationsharing request to the other access points. The information sharingrequest is a request for causing the access point that has not receivedthe probe request to provide the information to be shared for the otheraccess points. When the communication apparatus 10 a has received theinformation sharing request from another access point, the informationsharing unit 112 transmits information on the connected client to theother access points as the information to be shared only when thecommunication apparatus 10 a has not received the probe request from theclient 20.

The score calculation unit 113 is a program module that calculates, foreach of the access points included in the communication system 100, ascore, which is a value indicating the priority as the destination towhich the connection request client is connected using the informationregistered in the access point score table 153 in accordance with thescore calculation policy as shown in FIG. 11. Specifically, the scorecalculation unit 113 sets, when the access point whose score is to becalculated has received a probe request from the connection requestclient, a value indicating a high-order priority (e.g., “10”) as atemporary value of the score of this access point. On the other hand,when the access point whose score is to be calculated has not received aprobe request from the connection request client, the score calculationunit 113 uses a value indicating a low-order priority (e.g., “0”) as thescore of this access point. In place of the value indicating thelow-order priority, information indicating that the probe request hasnot been received (e.g., NULL) may be used as the score of this accesspoint.

Further, the score calculation unit 113 determines whether or not thereis a connected client in the access point that has received the proberequest based on the information indicating the presence or the absenceof the connected client, and when there is no connected client, thescore calculation unit 113 adds the value indicating the high-orderpriority (e.g., “10”) to the score of this access point. On the otherhand, when there is a connected client in the access point that hasreceived the probe request, the score calculation unit 113 compares themaximum communication speed of the connection request client with themaximum communication speed of the connected client, and adds, when themaximum communication speeds of these clients are the same, the valueindicating an intermediate priority (e.g., “5”) to the score of thisaccess point. On the other hand, when the maximum communication speedsof these clients are different from each other, the score calculationunit 113 does not add any value to the score of this access point.

Further, the score calculation unit 113 compares the radio waveintensity of the probe request that the access point has received fromthe connection request client with a threshold (e.g., “−60 dBm”) andadds, when the radio wave intensity of the connection request client isequal to or larger than the threshold, the value indicating thehigh-order priority (e.g., “10”) to the score of this access point. Thisthreshold may be such a radio wave intensity that allows the client 20to achieve its maximum communication speed (theoretical value) in thedata communication with the communication apparatus 10 a. On the otherhand, when the radio wave intensity of the connection request client issmaller than the threshold, the score calculation unit 113 does not addany value to the score of this access point. The score calculation unit113 registers the score of the access point thus calculated in theaccess point score table 153.

The connection necessity determination unit 114 is a program module thatdetermines whether or not it is necessary to establish the radiocommunication connection with the connection request client based on thescores calculated by the score calculation unit 113. Specifically, theconnection necessity determination unit 114 determines, when the scoreof the communication apparatus 10 a is the highest among the scorescalculated by the score calculation unit 113, that it is necessary toestablish the radio communication connection with the connection requestclient. When there is another access point that has a score that is thesame as the score of the communication apparatus 10 a, the connectionnecessity determination unit 114 determines, when the radio waveintensity of the probe request of the connection request client receivedby the communication apparatus 10 a is higher than the radio waveintensity of the probe request of the connection request client receivedby the other access point having the same score, that it is necessary toestablish the radio communication connection with the connection requestclient.

The connection processing unit 115 is a program module that executesconnection processing for establishing the radio communicationconnection with the connection request client. The connection processingunit 115 executes, when the connection necessity determination unit 114has determined that it is necessary to establish the radio communicationconnection with the connection request client, connection processing forestablishing the radio communication connection with the connectionrequest client.

The PHY chip 120 is a semiconductor integrated circuit that executesprocessing of a physical layer, which is a first layer of an OSIreference model. The PHY chip 120, which is arranged between the CPU110, and the wireless LAN interface 130 and the wired LAN interface 140,performs processing such as serialization or parallelization of data,D/A conversion, A/D conversion, and amplification of electric signals.Further, the PHY chip 120 includes a data transmission/reception unit121 and a radio wave intensity measurement unit 122.

The data transmission/reception unit 121 is a logic circuit thattransmits/receives data communicated with the client 20 or an externalapparatus such as a modem. The data transmission/reception unit 121forwards data received from the wireless LAN interface 130 and the wiredLAN interface 140 to the CPU 110 and forwards data received from the CPU110 to the wireless LAN interface 130 and the wired LAN interface 140.

The radio wave intensity measurement unit 122 is a logic circuit thatmeasures the intensity of the radio wave signal received from the client20 (RSSI: Received Signal Strength Indicator). The radio wave intensitymeasurement unit 122 measures, upon receiving the probe request from theclient 20, the intensity of the radio wave signal that forms the proberequest. The radio wave intensity measurement unit 122 provides theresults of measuring the intensity of the radio wave signal for thecontroller 111 in accordance with the request from the controller 111.

The wireless LAN interface 130 transmits an analog signal received fromthe PHY chip 120 to the client 20 or an external apparatus via thewireless LAN and supplies the analog signal received from the client 20or an external apparatus to the PHY chip 120.

The wired LAN interface 140 transmits the analog signal received fromthe PHY chip 120 to another access point or an external apparatus via awired LAN and supplies the analog signal received from another accesspoint or an external apparatus to the PHY chip 120.

The storage apparatus 150, which is a storage apparatus storing variouskinds of data or programs, or a data table, can be composed of a ROM ora RAM. In the storage apparatus 150, access point information 151 isstored, and the aforementioned client information table 152 and accesspoint score table 153 are constructed. The access point information 151,which is identification information of the access points 10 a-10 eincluded in the communication system 100, is registered in the accesspoint score table 153 as shown in FIG. 10 in advance. A MAC address orthe like of the access point can be used as the identificationinformation of the access point.

FIG. 3 is a block diagram showing main program modules included in thecommunication apparatus 10 a according to the first example embodiment.The communication apparatus 10 a includes, as main program modules, theinformation sharing unit 112, the score calculation unit 113, theconnection necessity determination unit 114, and the connectionprocessing unit 115 described above.

FIG. 4 is a sequence diagram showing one example of processing executedin the communication system 100 according to the first exampleembodiment of the present disclosure. In the example shown in FIG. 4, asshown in FIG. 1, it is assumed that the access points 10 a, 10 b, and 10c are arranged within the radio wave range of the client 20 and that theclient 20 is arranged within the radio wave range of the access points10 a, 10 b, and 10 c. Hereinafter, with reference to FIG. 4, thesequence of the processing executed when the client 20 establishes theradio communication connection with the access point 10 b will bedescribed.

When the client 20 establishes the radio communication connection withone of the access points 10 a-10 e included in the communication system100, the client 20 broadcasts the probe request via the wireless LAN.The access points 10 a, 10 b, and 10 c that have received the proberequest from the client 20 transmit the information to be shared toother access points via the wired LAN and broadcasts the informationsharing request. The access points 10 d and 10 e that have not receivedthe probe request from the client 20 each transmit, upon receiving theinformation sharing request from another access point, the informationto be shared to access points other than these access points 10 d and 10e.

Next, each of the access points 10 a, 10 b, and 10 c that have receivedthe probe request executes score calculation processing, calculates thescores for the access points 10 a-10 e included in the communicationsystem 100, and determines whether it needs to establish the radiocommunication connection with the client 20. Only the access point 10 bdetermined that it is necessary to establish the radio communicationconnection with the client 20 sends back the probe response to theclient 20, executes connection processing, and establishes the radiocommunication connection with the client 20.

FIGS. 5 and 6 are flowcharts showing processing executed by thecommunication apparatus according to the first example embodiment of thepresent disclosure. In the following, a case in which the access point10 a has received the probe request from the client 20 will bedescribed.

The processing shown in FIG. 5 starts from Step S100. In Step S101, thecontroller 111 of the access point 10 a acquires, from the radio waveintensity measurement unit 122, the radio wave intensity of theconnection request client 20 that has transmitted the probe request andacquires the maximum communication speed of the connection requestclient 20 included in the probe request, and registers the acquiredinformation in the client information table 152.

In Step S102, the controller 111 registers, in the access point scoretable 153, the information indicating that it has received the proberequest from the connection request client 20, the radio wave intensityof the connection request client 20, and the maximum communication speedof the connection request client 20 in association with theidentification information of the access point 10 a. The controller 111registers, when the maximum communication speed of the connected clientis registered in the client information table 152, besides theinformation on the connection request client, the information indicatingthat there is a connected client, and the maximum communication speed ofthe connected client in the access point score table 153 in associationwith the identification information of the access point 10 a. On theother hand, when the maximum communication speed of the connected clienthas not been registered in the client information table 152, thecontroller 111 registers, besides the information on the connectionrequest client, information indicating that there is no connected clientin association with the identification information of the access point10 a in the access point score table 153.

In Step S103, the information sharing unit 112 refers to the accesspoint information 151 stored in the storage apparatus 150 and specifiesthe other access points to which the information to be shared should betransmitted, that is, access points other than the access point 10 a,and transmits the information to be shared to these access points. Theinformation sharing unit 112 transmits, when the information indicatingthat there is a connected client has been registered in the access pointinformation 151, information indicating that the probe request has beenreceived, the maximum communication speed and the radio wave intensityof the connection request client 20, information indicating that thereis a connected client, and the maximum communication speed of theconnected client to the other access points as the information to beshared. On the other hand, when the information indicating that there isno connected client is registered in the access point information 151,the information sharing unit 112 transmits the information indicatingthat the probe request has been received, the maximum communicationspeed and the radio wave intensity of the connection request client 20,and the information indicating that there is no connected client to theother access points as the information to be shared.

In Step S104, the information sharing unit 112 broadcasts theinformation sharing request to the other access points 10 b to 10 e. InStep S105, the information sharing unit 112 determines whether or notthe information to be shared has been received from another accesspoint. When the information to be shared has not been received fromanother access point (NO), the information sharing unit 112 executesStep S105 again. On the other hand, when the information to be sharedhas been received from another access point (YES), the process proceedsto Step S106.

In Step S106, the information sharing unit 112 registers the informationto be shared received from the other access point in the access pointscore table 153. The information sharing unit 112 registers, when theinformation indicating that the probe request has been received fromanother access point has been received, the information indicating thatthe probe request has been received, the maximum communication speed andthe radio wave intensity of the connection request client in associationwith the identification information of the other access point in theaccess point score table 153. On the other hand, when the informationindicating that the probe request has not been received has beenreceived from another access point, the information sharing unit 112registers, in the access point score table 153, the informationindicating that the probe request has not been received in associationwith the identification information of the other access point. Further,the information sharing unit 112 registers, when information indicatingthat there is a connected client has been received from another accesspoint, information indicating that there is a connected client and themaximum communication speed of the connected client in association withthe identification information of the other access point in the accesspoint score table 153. On the other hand, when the informationindicating that there is no connected client has been received from theother access point, the information sharing unit 112 registers, in theaccess point score table 153, the information indicating that there isno connected client in association with the identification informationof the other access point.

In Step S107, the score calculation unit 113 executes, for the otheraccess points, the score calculation processing shown in FIG. 8, andcalculates the scores of the other access points. In Step S108, theinformation sharing unit 112 refers to the access point score table 153and determines whether the information to be shared has been receivedfrom all the access points. The information sharing unit 112 determineswhether or not the scores have been calculated for all the access pointsidentified by the access point identification information registered inthe access point score table 153, whereby it is possible to determinewhether the information to be shared has been received from all theaccess points.

When the information to be shared has not been received from all theaccess points (NO), the process goes back to Step S105. On the otherhand, when the information to be shared has been received from all theaccess points (YES), the process proceeds to Step S109 shown in FIG. 6.In Step S109, the connection necessity determination unit 114 refers tothe access point score table 153, compares the score of the access point10 a with the scores of the other access points, and determines whetheror not the score of the access point 10 a is the highest. When the scoreof the access point 10 a is not the highest score (NO), the process endswith Step S115. On the other hand, when the score of the access point 10a is the highest score (YES), the process proceeds to Step S110.

In Step S110, the connection necessity determination unit 114 refers tothe access point score table 153, compares the score of the access point10 a with the scores of the other access points, and determines whetheror not there is an access point in which a score is the same as that ofthe access point 10 a. When there is no access point in which the scoreis the same as the score of the access point 10 a (NO), the processproceeds to Step S112. On the other hand, when there is an access pointin which the score is the same as the score of the access point 10 a(YES), the process proceeds to Step S111. In Step S111, the connectionnecessity determination unit 114 refers to the access point score table153, compares the radio wave intensity of the connection request client20 associated with the identification information of the access point 10a (that is, the radio wave intensity of the connection request client 20that the access point 10 a has received) with the radio wave intensityof the connection request client 20 associated with the identificationinformation of the access point in which the score is the same as thatof the access point 10 a (that is, the radio wave intensity of theconnection request client 20 received by the access point in which thescore is the same), and determines whether or not the radio waveintensity of the connection request client 20 that the access point 10 ahas received is the highest. When the radio wave intensity of theconnection request client 20 that the access point 10 a has received isnot the highest (NO), the process ends with Step S115. On the otherhand, when the radio wave intensity of the connection request client 20that the access point 10 a has received is the highest (YES), theprocess proceeds to Step S112.

In Step S112, the connection processing unit 115 transmits a proberesponse to the client 20 who has transmitted the probe request. In StepS113, the connection processing unit 115 executes connection processingwith the client 20. In Step S114, the connection processing unit 115registers the information indicating the maximum communication speed ofthe client 20 included in the probe request in the client informationtable 152 as the maximum communication speed of the connected client andthe processing is ended in Step S115.

FIG. 7 is a flowchart showing processing executed by the communicationapparatus according to the first example embodiment of the presentdisclosure. The processing shown in FIG. 7 is processing for allowingthe access point that has not received the probe request from the client20, that is, the access point arranged in the outside of the radio waverange of the client 20 to provide the information to be shared of thisaccess point for the other access points. Hereinafter, a case in whichthe access point 10 d has received the information sharing request fromanother access point will be described.

The processing shown in FIG. 7 starts from Step S200. In Step S201, theinformation sharing unit 112 of the access point 10 d refers to theaccess point score table 153 and determines whether or not the accesspoint 10 d has received the probe request. In this example embodiment,the initial value of the column in which information indicating thepresence or the absence of the probe request in the access point scoretable 153 is registered is NULL. When the access point 10 d has receivedthe probe request, information indicating that the probe request hasbeen received is registered in this column in Step S102 shown in FIG. 5.Therefore, the information sharing unit 112 is able to determine whetheror not the access point 10 d has received the probe request by referringto the information registered in the column.

When the access point 10 d has received the probe request (YES), theprocessing is ended in Step S203. On the other hand, when the accesspoint 10 d has not received the probe request (NO), the process moves toStep S202. In Step S202, the information sharing unit 112 refers to theaccess point information 151 stored in the storage apparatus 150,specifies the other access points to which the information to be sharedshould be transmitted, that is, the access points 10 a to 10 c and 10 eother than the access point 10 d, transmits the information to be sharedto these access points, and the processing is ended in Step S203. Theinformation sharing unit 112 refers to the client information table 152,and when the maximum communication speed of the connected client hasbeen registered, the information sharing unit 112 transmits theinformation indicating that the connected client is present, the maximumcommunication speed of the connected client, and the informationindicating that the probe request has not been received to the otheraccess points as the information to be shared. On the other hand, whenthe maximum communication speed of the connected client has not beenregistered in the client information table 152, the information sharingunit 112 transmits the information indicating that there is no connectedclient and the information indicating that the probe request has notbeen received to the other access points as the information to beshared.

FIG. 8 is a flowchart showing one example embodiment of the scorecalculation processing. FIG. 8 starts from Step S300, and in Step S301,the score calculation unit 113 initializes the variable Score by “0”. InStep S302, the score calculation unit 113 refers to the access pointscore table 153 and determines whether or not the access point whosescore is to be calculated has received the probe request. When theaccess point whose score is to be calculated has not received the proberequest (NO), the process proceeds to Step S310. On the other hand, whenthe access point whose score is to be calculated has received the proberequest (YES), the process proceeds to Step S303. In Step S303, thescore calculation unit 113 sets “10” as the variable Score.

In Step S304, the score calculation unit 113 refers to the access pointscore table 153 and determines whether there is no connected client inthe access point whose score is to be calculated. When there is noconnected client in the access point whose score is to be calculated(YES), the process proceeds to Step S305. In Step S305, the scorecalculation unit 113 adds “10” to the value set in the variable Scoreand the process proceeds to Step S308. On the other hand, when there isa connected client in the access point whose score is to be calculated(NO), the process proceeds to Step S306.

In Step S306, the score calculation unit 113 refers to the access pointscore table 153, compares the maximum communication speed of theconnection request client associated with the identification informationof the access point whose score is to be calculated with the maximumcommunication speed of the connected client, and determines whether ornot the maximum communication speeds of these clients are the same. Whenthe maximum communication speeds of these clients are different fromeach other (NO), the process goes to Step S308. On the other hand, whenthe maximum communication speeds of these clients are the same (YES),the process proceeds to Step S307. In Step S307, the score calculationunit 113 adds “5” to a value set in the variable Score.

In Step S308, the score calculation unit 113 refers to the access pointscore table 153 and determines whether the radio wave intensity of theconnection request client associated with the identification informationof the access point whose score is to be calculated is equal to orlarger than a threshold (e.g., “−60 dBm”). When the radio wave intensityof the connection request client is smaller than the threshold (NO), theprocess proceeds to Step S310. On the other hand, when the radio waveintensity of the connection request client is equal to or larger thanthe threshold (YES), the process proceeds to Step S309. In Step S309,the score calculation unit 113 adds the point “10” to the variableScore. In Step S310, the score calculation unit 113 registers the valueset in the variable Score in the access point score table 153 as ascore, and the process is ended in Step S311.

According to the first example embodiment, the following effects areobtained. That is, since the score calculation unit 113 gives ahigh-order priority to the access point that has not established theradio communication connection with another client, this access pointpreferentially establishes the radio communication connection with theconnection request client. Accordingly, waiting time that is due to thedata communication between this access point and another client does notoccur, whereby it is possible to reduce the round-trip time between thenewly connected client and this access point.

Further, the score calculation unit 113 compares, when there is aconnected client in the access point whose score is to be calculated,the maximum communication speed of the connection request client withthe maximum communication speed of the connected client, and gives, whenthe maximum communication speeds of these clients are the same, theintermediate priority to this access point. On the other hand, the scorecalculation unit 113 gives, when the maximum communication speeds ofthese clients are different from each other, the low-order priority tothis access point. Accordingly, the access point that has establishedthe radio communication connection with the connected client having themaximum communication speed that is the same as that of the connectionrequest client preferentially establishes the radio communicationconnection with the connection request client. Therefore, the connectionrequest client for high-speed communication is able to preferentiallyestablish the radio communication connection with the access point thathas established the radio communication connection with the connectedclient for high-speed communication, not with the access point that hasestablished the radio communication connection with the connected clientfor low-speed communication. As a result, it is possible to reducewaiting time due to the data communication between the connected clientand the access point (that is, waiting time of the newly connectedclient) and to reduce the waiting time that is due to the datacommunication between the newly connected client and this access point(that is, waiting time of the connected client). Therefore, even whenthere is a connected client in the access point to be connected, theround-trip time between the client and the access point can be reduced.

Further, the score calculation unit 113 gives a high-order priority toan access point regarding which an intensity of the radio waves of theconnection request client is equal to or larger than the threshold andgives a low-order priority to an access point regarding which anintensity of the radio waves of the connection request client is smallerthan the threshold. Accordingly, the access point regarding which thereceived radio wave intensity is high preferentially establishes theradio communication connection with the connection request client.Therefore, the access point and the client are able to perform datacommunication using radio waves having a high intensity, the executionspeed in this data communication can be increased, and the round-triptime between the client and the access point can be reduced.

Further, the connection necessity determination unit 114 determines,when there is another access point that has a score that is the same asthe score of its access point, that it is necessary to establish theradio communication connection with the connection request client whenthe intensity of the radio waves of the connection request client forits access point is higher than the intensity of the radio waves of theconnection request client received by another access point. Accordingly,the access point having a high received radio wave intensitypreferentially establishes the radio communication connection with theconnection request client. Therefore, the access point and the clientare able to perform data communication using radio waves having a highintensity, the execution speed in this data communication can beincreased, and the round-trip time between the client and the accesspoint can be reduced.

Second Example Embodiment

FIG. 12 is a block diagram showing a detailed configuration of an accesspoint management apparatus 30 according to a second example embodimentof the present disclosure. In the second example embodiment, acommunication system 100 includes communication apparatuses 10 a-10 eand the access point management apparatus 30, and the access pointmanagement apparatus 30 determines an access point that should beconnected to a connection request client. In this example embodiment,the communication apparatuses 10 a-10 e may have a configuration that itdoes not include the score calculation unit 113, the connectionnecessity determination unit 114, and the access point score table 153.

The access point management apparatus 30, which is an informationprocessing apparatus that can communicate with the communicationapparatuses 10 a-10 e via a wired LAN network, determines thecommunication apparatus that should be connected to the connectionrequest client and establishes the radio communication connectionbetween the communication apparatus and the connection request client.The access point management apparatus 30 includes a CPU 310, a wired LANinterface 340, and a storage apparatus 350.

The CPU 310 is an arithmetic apparatus that executes various kinds ofprograms. The CPU 310 extends the selective communication connectionprogram according to the present disclosure stored in a ROM to a RAM andexecutes this program, thereby achieving the selective communicationconnection method according to the present disclosure. The selectivecommunication connection program includes a controller 311, a sharedinformation acquisition unit 312, a score calculation unit 313, aconnection destination determination unit 314, and a connectionprocessing unit 315, which are program modules.

The controller 311 plays a main role of achieving the function of theaccess point management apparatus 30, and executes various types ofprocessing by controlling other program modules or function units. Theshared information acquisition unit 312 is a program module thatacquires the information to be shared from an access point included inthe communication system 100. The shared information acquisition unit312 broadcasts, when a notification indicating that the access point hasreceived the probe request from the connection request client (proberequest notification) has been received, the information sharing requestvia the wired LAN and acquires the information to be shared from theaccess point.

The score calculation unit 313 is a program module that calculates thescore for each access point included in the communication system 100using the information registered in the access point score table 153,similar to the score calculation unit 113 according to the first exampleembodiment. The connection destination determination unit 314 is aprogram module that determines the access point that should establishthe radio communication connection with the connection request clientbased on the scores calculated by the score calculation unit 313. Theconnection processing unit 315 is a program module for causing theconnection destination determination unit 314 to establish the radiocommunication connection between the access point and the connectionrequest client.

FIG. 13 is a block diagram showing main program modules included in theaccess point management apparatus 30 according to the second exampleembodiment. The access point management apparatus 30 includes, as mainprogram modules, the shared information acquisition unit 312, the scorecalculation unit 313, the connection destination determination unit 314,and the connection processing unit 315 described above.

FIG. 14 is a sequence diagram showing one example of processing executedin the communication system 100 according to the second exampleembodiment of the present disclosure. In the example shown in FIG. 14,it is assumed that the access points 10 a, 10 b, and 10 c are arrangedwithin the radio wave range of the client 20 and the client 20 isarranged within the radio wave range of the access points 10 a, 10 b,and 10 c, like in FIG. 1 according to the first example embodiment.Hereinafter, with reference to FIG. 14, the sequence of the processingexecuted when the client 20 establishes the radio communicationconnection with the access point 10 b will be described. While theaccess point 10 e is not shown in FIG. 14, the behavior of the accesspoint 10 e is similar to that of the access point 10 d.

When the client 20 establishes the radio communication connection withan access point included in the communication system 100, the client 20broadcasts the probe request via the wireless LAN. The access points 10a, 10 b, and 10 c that have received the probe request from the client20 each transmit a probe request notification to the access pointmanagement apparatus 30 via the wired LAN. Upon receiving the proberequest notification from the access points, the access point managementapparatus 30 refers to the access point information 151 and specifiesall the access points included in the communication system 100, andtransmits an information sharing request to these access points via thewired LAN.

The access points 10 a-10 e each transmit, upon receiving theinformation sharing request from the access point management apparatus30, information to be shared of itself to the access point managementapparatus 30. The access points 10 a, 10 b, and 10 c that have receivedthe probe request from the client 20 each transmit, along with theinformation indicating that it has received the probe request, themaximum communication speed and the radio wave intensity of the client20 to the access point management apparatus 30. On the other hand, theaccess points 10 d and 10 e that have not received the probe requestfrom the client 20 each transmit information indicating that it has notreceived the probe request to the access point management apparatus 30.Further, these access points each transmit, when there is a connectedclient, along with information indicating that there is a connectedclient, the maximum communication speed of the connected client to theaccess point management apparatus 30. On the other hand, when there isno connected client, the access point transmits information indicatingthat there is no connected client to the access point managementapparatus 30.

The access point management apparatus 30 executes, upon receiving theinformation to be shared from the access points 10 a-10 e, the scorecalculation processing and calculates the scores for the access pointsincluded in the communication system 100. Then the access pointmanagement apparatus 30 determines the access point that shouldestablish the radio communication connection with the client 20 based onthe scores of the access points that have been calculated, and transmitsa probe response instruction to the access point. When the access point10 b has received the probe response instruction from the access pointmanagement apparatus 30, the access point 10 b sends back the proberesponse to the client 20 and establishes the radio communicationconnection with the client 20.

FIG. 15 is a flowchart showing processing executed by the access pointmanagement apparatus 30 according to the second example embodiment ofthe present disclosure. The processing shown in FIG. 15 starts from StepS400 when the access point management apparatus 30 has received theprobe request notification from one of the communication apparatuses 10a-10 e. Since it is possible that the access point management apparatus30 may receive the probe request notification from a plurality ofcommunication apparatuses substantially at the same time, when theaccess point management apparatus 30 has received the probe requestnotification from one communication apparatus and executed theprocessing shown in FIG. 15, the access point management apparatus 30may be configured not to execute this processing for a certain period oftime.

In Step S401, the shared information acquisition unit 312 of the accesspoint management apparatus 30 transmits the information sharing requestto the access point included in the communication system 100. In StepS402, the shared information acquisition unit 312 determines whether theinformation to be shared has been received from the access point. Whenthe information to be shared has not been received from the access point(NO), the shared information acquisition unit 312 executes Step S402again. On the other hand, when the information to be shared has beenreceived from the access point (YES), the process proceeds to Step S403.

In Step S403, the shared information acquisition unit 312 registers theinformation to be shared received from the access point in the accesspoint score table 153. Upon receiving the information indicating thatthe probe request has been received from the access point, the sharedinformation acquisition unit 312 registers, in the access point scoretable 153, the information indicating that the probe request has beenreceived, and the maximum communication speed and the radio waveintensity of the connection request client in association with theidentification information of the access point. On the other hand, uponreceiving the information indicating that the probe request has not beenreceived from the access point, the shared information acquisition unit312 registers, in the access point score table 153, the informationindicating that the probe request has not been received in associationwith the identification information of the access point. Further, theshared information acquisition unit 312 registers, when the informationindicating that there is a connected client has been received from theaccess point, the information indicating that there is a connectedclient and the maximum communication speed of the connected client inassociation with the identification information of the access point inthe access point score table 153. On the other hand, when theinformation indicating that there is no connected client has beenreceived from the access point, the shared information acquisition unit312 registers, in the access point score table 153, the informationindicating that there is no connected client in association with theidentification information of the access point.

In Step S404, the score calculation unit 313 executes, for this accesspoint, the score calculation processing shown in FIG. 8 and calculatesthe score of this access point. In Step S405, the shared informationacquisition unit 312 refers to the access point score table 153 anddetermines whether the information to be shared has been received fromall the access points. The shared information acquisition unit 312determines whether or not the scores have been calculated for all theaccess points identified by the access point identification informationregistered in the access point score table 153, whereby it is possibleto determine whether the information to be shared has been received fromall the access points.

When the information to be shared has not been received from all theaccess points (NO), the process returns to Step S402. On the other hand,when the information to be shared has been received from all the accesspoints (YES), the process proceeds to S406. In Step S406, the connectiondestination determination unit 314 refers to the access point scoretable 153 and specifies the access point in which the score is thehighest. In Step S407, the connection destination determination unit 314determines whether or not the number of access points that have beenspecified is plural. When the number of access points that have beenspecified is one (NO), the process branches to Step S409. On the otherhand, when the number of access points that have been specified isplural (YES), the process branches to Step S408. In Step S408, theconnection destination determination unit 314 refers to the access pointscore table 153 and specifies the access point regarding which the radiowave intensity is the highest among the plurality of access points thathave been specified. In Step S408, the connection processing unit 315transmits the probe response instruction to the access point specifiedby the connection destination determination unit 314, and the processingis ended in Step S410.

In the second example embodiment, besides the effects obtained in thefirst example embodiment, the following effects are obtained. That is,the access point management apparatus 30 determines the access pointthat should be connected to the connection request client andestablishes the radio communication connection between the above accesspoint and the connection request client. Therefore, it is possible toreduce the processing load of the access point compared with the exampleembodiment in which it is determined whether the access point that hasreceived the probe request should be connected to the connection requestclient.

Third Example Embodiment

In a third example embodiment, the score calculation unit 113 accordingto the first example embodiment and the score calculation unit 313according to the second example embodiment compare the maximumcommunication speed of the connection request client with the maximumcommunication speed of the connected client and calculates the score forgiving the intermediate priority to the access point in which adifference between the maximum communication speeds of these clients isequal to or smaller than a threshold. This threshold may be a desiredvalue (0 or larger) where it is recognized that the maximumcommunication speeds are substantially the same. Further, the scorecalculation unit 113 calculates the score that gives a low-orderpriority to the access point in which a difference between the maximumcommunication speeds of these clients exceeds the threshold. That is,when the maximum communication speeds of these clients are substantiallythe same even when they are not completely the same, the scorecalculation unit 113 gives the intermediate priority to the accesspoint. Accordingly, according to the third example embodiment, besidesthe effects obtained in the first and second example embodiments, thefollowing effect can be obtained. That is, even when the maximumcommunication speed of the connection request client and the maximumcommunication speed of the connected client are substantially the same,the intermediate priority can be given to the access point, and thenumber of candidates of the access points that can reduce the round-triptime between the client and the access point can be increased.

Fourth Example Embodiment

While the case in which one connected client establishes the radiocommunication connection with an access point in the communicationsystem 100 has been described in the aforementioned example embodiments,when a plurality of connected clients establish the radio communicationconnection with the access point, it is possible that the waiting timeof a client to be newly connected may increase as a result of datacommunication between these connected clients and this access point.Therefore, in the fourth example embodiment, when there are a pluralityof connected clients in the access point whose score is to becalculated, the score calculation unit 113 according to the firstexample embodiment and the score calculation unit 313 according to thesecond example embodiment calculate the score for giving a low-orderpriority to the access point even when the maximum communication speedof the connection request client and the maximum communication speed ofthe connected client are the same. On the other hand, when there is oneconnected client in the access point whose score is to be calculated andthe maximum communication speed of the connection request client is thesame as the maximum communication speed of the connected client, thescore calculation unit 113 calculates the score for giving theintermediate priority to the access point, like in the aforementionedexample embodiments. Accordingly, an access point that has establishedthe radio communication connection with one connected clientpreferentially establishes the radio communication connection with theconnection request client over the access point that has established theradio communication connection with the plurality of connected clients.Therefore, it is possible to reduce the waiting time that is due to thedata communication between another connected client and this accesspoint (that is, waiting time of the newly connected client) and toreduce the waiting time that is due to the data communication betweenthe newly connected client and this access point (that is, waiting timeof the other connected client). Therefore, even in a case in which thereis an access point that has established the radio communicationconnection with the plurality of connected clients in the communicationsystem 100, the round-trip time between the client and the access pointcan be reduced.

Other Example Embodiments

While the CPU 110 extends the controller 111, the information sharingunit 112, the score calculation unit 113, the connection necessitydetermination unit 114, and the connection processing unit 115, whichare program modules, to the RAM and executes them in the aforementionedexample embodiments, the aforementioned processing may be executed bycausing these program modules to be mounted on a logic circuit in otherexample embodiments. Further, while the maximum communication speed(theoretical value) of the client is used as a parameter for calculatingthe scores of the access points in the aforementioned exampleembodiments, a maximum communication speed (measured value) that theclient is able to achieve may instead be used in the other exampleembodiments.

In the aforementioned examples, the program can be stored and providedto a computer using any type of non-transitory computer readable media.Non-transitory computer readable media include any type of tangiblestorage media. Examples of non-transitory computer readable mediainclude magnetic storage media (such as flexible disks, magnetic tapes,hard disk drives, etc.), optical magnetic storage media (e.g.,magneto-optical disks), CD-ROM, CD-R, CD-R/W, and semiconductor memories(such as mask ROM, Programmable ROM (PROM), Erasable PROM (EPROM), flashROM, RAM, etc.). The program(s) may be provided to a computer using anytype of transitory computer readable media. Examples of transitorycomputer readable media include electric signals, optical signals, andelectromagnetic waves. Transitory computer readable media can providethe program to a computer via a wired communication line (e.g., electricwires, and optical fibers) or a wireless communication line.

While the present disclosure has been described with reference to theexample embodiments, the present disclosure is not limited by the aboveexample embodiments. Various changes that may be understood by thoseskilled in the art may be made to the configurations and the details ofthe present disclosure within the scope of the present disclosure.

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2018-173806, filed on Sep. 18, 2018, thedisclosure of which is incorporated herein in its entirety by reference.

REFERENCE SIGNS LIST

-   10 a˜10 e Access Point-   20 Client-   100 Communication System-   112 Information Sharing Unit-   113 Core Calculation Unit-   114 Connection Necessity Determination Unit-   115 Connection Processing Unit-   30 Access Point Management Apparatus-   312 Shared Information Acquisition Unit-   313 Core Calculation Unit-   314 Connection Destination Determination Unit-   315 Connection Processing Unit

1. A communication apparatus that functions as an access point, thecommunication apparatus comprising: information sharing means fortransmitting/receiving, when a radio communication connection has beenrequested from a first client, information to be shared with anotheraccess point; score calculation means for calculating, for the accesspoint and the other access point, scores indicating their priority as adestination to which the first client is connected using the informationto be shared; connection necessity determination means for determiningwhether or not it is necessary to establish a radio communicationconnection with the first client based on the scores calculated by thescore calculation means; and connection processing means forestablishing a radio communication connection with the first client whenthe connection necessity determination means has determined that it isnecessary to establish the radio communication connection, wherein theinformation to be shared includes information indicating the presence orthe absence of a second client that has already established the radiocommunication connection with an access point, the score calculationmeans calculates a score for giving a high-order priority to an accesspoint in which the radio communication connection with the second clienthas not been established based on the information indicating thepresence or the absence of the second client, and the connectionnecessity determination means determines that it is necessary toestablish the radio communication connection with the first client whenthe score of the access point is the highest among the scores calculatedby the score calculation means.
 2. The communication apparatus accordingto claim 1, wherein the information to be shared further includes acommunication speed of the first client and a communication speed of thesecond client, and the score calculation means compares thecommunication speed of the first client with the communication speed ofthe second client, calculates a score for giving an intermediatepriority to an access point in which these communication speeds are thesame, and calculates a score for giving a low-order priority to anaccess point in which these communication speeds are different from eachother.
 3. The communication apparatus according to claim 1, wherein theinformation to be shared further includes a communication speed of thefirst client and a communication speed of the second client, and thescore calculation means compares the communication speed of the firstclient with the communication speed of the second client, calculates ascore for giving an intermediate priority to an access point in which adifference between these communication speeds is equal to or smallerthan a first threshold, and calculates a score for giving a low-orderpriority to an access point in which a difference between thecommunication speeds exceeds the first threshold.
 4. The communicationapparatus according to claim 1, wherein the information to be sharedfurther includes an intensity of radio waves of the first clientreceived by an access point, and the score calculation means calculatesa score that gives a high-order priority to an access point regardingwhich an intensity of radio waves of the first client is equal to orlarger than a second threshold and calculates a score that gives alow-order priority to an access point regarding which an intensity ofradio waves of the first client is smaller than a second threshold. 5.The communication apparatus according to claim 4, wherein the connectionnecessity determination means determines, when there is another accesspoint that has a score that is the same as the score of the accesspoint, that it is necessary to establish the radio communicationconnection with the first client when the intensity of radio waves ofthe first client that the access point has received is higher than theintensity of radio waves of the first client that the other access pointhaving the same score as that of the access point has received.
 6. Anaccess point management apparatus comprising: shared informationacquisition means for acquiring information to be shared from aplurality of access points; score calculation means for calculating, forthe plurality of access points, scores indicating their priority as aconnection destination of a first client who has requested a radiocommunication connection using the information to be shared; connectiondestination determination means for determining an access point thatshould establish a radio communication connection with the first clientbased on the scores calculated by the score calculation means; andconnection processing means for establishing a radio communicationconnection between the access point determined by the connectiondestination determination means and the first client, wherein theinformation to be shared includes information indicating the presence orthe absence of a second client that has already established the radiocommunication connection with an access point, the score calculationmeans calculates a score for giving a high-order priority to an accesspoint in which the radio communication connection with the second clienthas not been established based on the information indicating thepresence or the absence of the second client, and the connectiondestination determination means determines an access point whose scorecalculated by the score calculation means is the highest to be an accesspoint that should establish a radio communication connection with thefirst client.
 7. The access point management apparatus according toclaim 6, wherein the information to be shared further includes acommunication speed of the first client and a communication speed of thesecond client, and the score calculation means compares thecommunication speed of the first client with the communication speed ofthe second client, calculates a score for giving an intermediatepriority to an access point in which these communication speeds are thesame, and calculates a score for giving a low-order priority to anaccess point in which these communication speeds are different from eachother.
 8. The access point management apparatus according to claim 6,wherein the information to be shared further includes an intensity ofradio waves of the first client received by the access point, and thescore calculation means calculates a score that gives a high-orderpriority to an access point regarding which an intensity of radio wavesof the first client is equal to or larger than a second threshold andcalculates a score that gives a low-order priority to an access pointregarding which an intensity of radio waves of the first client issmaller than a second threshold.
 9. A selective communication connectionmethod for selectively establishing communication connection with aclient, the method comprising the steps of: transmitting/receivinginformation to be shared with another access point when a radiocommunication connection has been requested from a first client;calculating, for an access point and the other access point, scoresindicating their priority as a destination to which the first client isconnected using the information to be shared; determining whether or notit is necessary to establish a radio communication connection with thefirst client based on the calculated scores; and establishing the radiocommunication connection with the first client when it has beendetermined that it is necessary to establish the radio communicationconnection, wherein the information to be shared comprises informationindicating the presence or the absence of the second client that hasalready established the radio communication connection with an accesspoint, the step of calculating the score comprises calculating a scorefor giving a high-order priority to an access point in which the radiocommunication connection with the second client has not been establishedbased on the information indicating the presence or the absence of thesecond client, and the step of determining whether it is necessary toestablish the radio communication connection comprises determining thatit is necessary to establish the radio communication connection with thefirst client when the score of the access point is the highest among thescores that have been calculated.
 10. A non-transitory computer readablemedium storing a selective communication connection program executed ina communication apparatus including an arithmetic apparatus, theselective communication connection program causing the arithmeticapparatus to perform the steps of: transmitting/receiving information tobe shared with another access point when a radio communicationconnection has been requested from a first client; calculating, for anaccess point and the other access point, scores indicating theirpriority as a destination to which the first client is determiningwhether or not it is necessary to establish a radio communicationconnection with the first client based on the scores; and establishingthe radio communication connection with the first client when it hasbeen determined that it is necessary to establish the radiocommunication connection, wherein the information to be shared comprisesinformation indicating the presence or the absence of a second clientthat has already established the radio communication connection with anaccess point, the step of calculating the score comprises calculating ascore for giving a high-order priority to an access point in which theradio communication connection with the second client has not beenestablished based on the information indicating the presence or theabsence of the second client, and the step of determining whether it isnecessary to establish the radio communication connection comprisesdetermining, when the score of the access point is the highest among thescores that have been calculated, that it is necessary to establish theradio communication connection with the first client.